Gye Greene's Thoughts

Gye Greene's Thoughts (w/ apologies to The Smithereens and their similarly-titled album!)

Friday, May 15, 2015

Did woodworking demo at school

My sons' class was doing an "old technology" unit in school, and parents were asked to loan various examples of "old technology" to the class.  I brought in a cassette walkman, a CRT computer monitor (which a boy argued with me that it was a t.v.!), a small scorp (see below), a (slightly broken!) marking gauge (below), and a wooden jack plane (see also below).

The teacher appreciated the loan -- but then asked when I could come by to demonstrate the tools.  Ah!  Sure.

I had arranged to do my hand tool woodworking demo this afternoon (Friday) -- because I had to leave work early anyhow, to pick up the boys right after school for a birthday party.  So, that morning I loaded up my gear in the back of our small-ish SUV.  However, when we got to the boys' classroom I saw that the class' schedule for the day (posted in the window) included an afternoon class that I didn't expect to be cancelled just for me.

I tried to find the teacher to clarify the situation, but she wasn't around.  Then, just as the morning bell rang, the vice-principal appeared:  she said that the boys' teacher had phoned in sick, but the substitute teacher would not be arriving for a few hours.  So, the vice-principal would have to cover the class.

I asked if I could just do my woodworking demo in the morning -- as it would take the same amount of time out of my day to get to work late, or leave work early.  The vice-principal was very willing to let me do the demo in the morning:  otherwise, she didn't know what she was going to do with the kids until the substitute got there.


I moved my car, and managed to find a parking space really close to the classroom.  And I explained the situation to two of the parents, who helped me unload my car.  I reckon it took me about 15 minutes to set up.

Here's my pile of gear in the car:

With a little cleverness, I had managed to fit -- under the privacy screen! -- a plastic tub, a wooden tool tote, a milk crate, some pieces of wood, and a small portable workbench... (behind the orange tub) a bunch of clamps; across the legs of the workbench, two handsaws; and between the legs of the small workbench, two 20kg (44 lb) bags of sand, for ballast.  In the back seat, I had a large plank.

Here's my basic setup, arranged around a dogbone-shaped cement bench just outside the boys' classroom.  I arranged the various props by themes -- discussed in a moment.  Under the workbench, you can see the plank (dangerously?) sticking out -- but it supports the 40kg (88lbs) of ballast that weights the bench down.

I took this photo at the end of my demo - so this shows how I finished.

I started off the session by talking about wood.  I held up a short plank of wood that I had split "from the round" (i.e. from a short log), and talked about wood.

I asked the class where wood comes from.  (Trees!)  Then I asked if trees were pretty much the same now, as it was fifty years ago.  (Yes.)  How about now, compared to one hundred years ago?  (Yes.)  How about five hundred years ago?  (Yes!)

OK, then.  So, there are different types of tools for making things out of wood.  A lot of new types of tools use electricity.  But older types of tools don't use electricity -- because a long time ago people didn't have electricity in their homes.  But the wood doesn't care whether you use old tools or new tools -- because the trees haven't changed -- so the wood hasn't changed -- so the old tools and the new tools both work just fine.  (But, see below.)

I also held up a plastic tool tote, and a wooden tool tote.

I told then that a long time ago, most things were made out of wood, and or metal, because plastic hadn't been invented yet.  The nice thing about making things out of wood is that a person can make things for themselves, or have a friend or family member make it for you.  This tool tote was made by my grandfather, who made a lot of things out of wood, for the family.

But now-a-days, with plastic -- it's very cheap to make (you just get a shape, and squirt the melted plastic into the shape, let it get hard and then pop it out).  But it's usually not as strong -- and also, I think plastic doesn't look as nice as wood.

Here's another example.  If you want corners to be the same exact angle as a square or rectangle, you need a tool like this so you can make sure.  The yellow plastic one is called a "Speed square".  But a long time ago they used to use the "try square".  What is the yellow tool made out of?  (Plastic!)  Right!  And what is the try square made out of?  (Wood!  Metal!)  Yep -- that's right.  And, again -- I think the wooden tool looks better.  But both do the job that you need them to do.

I then talked about working with wood.  I held up one of my short planks and pointed out the fibres, which were pretty obvious because I'd split the plank with wedges, rather than sawing it -- so there were many shredded, trailing bits.  I demonstrated, with a heavy hammer, and a splitting wedge... 

...that splitting off a piece with the grain is pretty fast, and pretty easy.  Whereas trying to split it across the grain (Whack!) doesn't do much except make a dent.

This led to saws.  If you want to make a piece of wood smaller, you could use a saw.  How many of you have seen a saw that looks like this, around your house?  (About a third of the class.)  Well, these saws are fast -- but they are pretty loud-- so you need to protect your hearing with hearing protectors.  And you need to wear safety goggles in case pieces fly at your face.  And these types of saw creates teeny, tiny pieces of sawdust, which you can accidentally breathe in -- so you need to wear a dust mask (whoops!  which I forgot to bring).

But, these types of saw were too expensive for most people, until about the time that your grandparents were little kids.  Before that time, most people used saws like these:

I explained that the zig-zaggy bits are called "teeth", and that the larger the teeth, the faster the cut -- but they also make the end of the wood more messy than the smaller teeth.  I said that the smallest one is called a "backsaw".  (The other two are both filed for rip cutting -- but I didn't go into crosscut versus rip.)

Then I did a little demonstration, by cutting a scrap piece of wood (not shown), and seeing if the saw with the larger teeth really did cut faster.

But, first!  If you're going to make a cut, you have to make a line -- so you know where to cut!  So I showed the class how you use a trysquare (left) and a marking knife (home-made, second from right), or else a marking gauge (either of the two wooden things), to draw a line.  I demonstrated how, with hand-tool woodworking, you often don't actually measure things -- because you're just making cuts relative to other pieces of wood.

So, I made two cut lines, using a marking gauge, and then used the small workbench (really, a large sawbench), and cut the same piece twice -- with the class chanting "one alligator, two alligator...", to time me.  With the medium-toothed saw (far right, earlier photo), it took "16 alligators" to cut through, whereas the larger saw (in the middle, earlier photo) took "10 alligators" -- and that was even with it binding once (which slowed me down).

I then wanted to talk about making holes -- but before I attached the wood to the workbench, I discussed clamps.

I explained that the wooden clamps were a very old style -- especially if they used wooden threads instead of metal (I actually said "this part here", instead of "threads").  The next ones over (I held them up, in turn) are "G-clamps" -- or sometimes "C-clamps", because they look like those letters.   (One kid denied that it looked like a "G" -- and after we went back and forth, I told him that he had no imagination.)

The next clamp (with the red handle) is an "F-clamp" (same reason).  And the final type is a bar clamp, which is the most modern of the four.

Then I used some of the clamps to attach my board to the workbench (with a sacrificial board underneath it -- so I didn't drill into the workbench itself).

And, I talked about drills.  Holding each one up, I showed how the grey drill uses electricity (and is made of plastic!) -- whereas in the old days they might use (from left to right) a gimlet, a bradawl (I mimed its use), a brace and bit, or an "eggbeater" style drill.  I also showed how a power drill might use a spade bit to drill a big hole, whereas in the old days you would use a brace and bit.

And then I drilled a hole (not shown) with the brace and bit.

Somewhat arbitrarily, I then talked about scorps --
-- and how they were used to scoop out things, such as the seats of wooden chairs.  (The vice-principal remarked that she didn't know that.)

And I also talked about hammers and mallets.  I told them that basically, if the hitting part is made out of metal, it's a hammer; if the hitting part is made of wood, or rubber, or plastic, then it's a mallet.  Then I held up each of the below and had them declare whether it was a hammer!  Or a mallet!  (The vice-principal also said that she didn't know that, either!)

Finally, I talked about handplanes.  I didn't go into detail -- but I did say that really old ones are wooden, whereas the ones that came out about a hundred years ago are made of metal.

I then discussed (briefly!) about how a slab of wood is converted into a board.  I clamped some battens (i.e. pieces of wood, used as stops) to the workbench, and using the wooden plane (which I've set up as a scrub plane -- it takes big bites!), I briefly demonstrated flattening the face of a board.

Finally (audience participation!), I switched to the metal plane (a #4 smoother), which I'd set to take a very fine cut -- because they're little kids, so a fine setting would be easier for them to push.  The kids lined up behind the board; I stood on the far side of the workbench (which screwed up my back a little, hunching over) and fell into a pretty stable pattern of:

-(I hold it, to demonstrate) Right hand goes on the back handle, point your finger
-Left hand (slap!) goes onto the round knob
-Your turn!  (hand it to the child; correct the hand position)
-Have them take three swipes, with me pinching the cheeks of the handplane and pulling it forward, to assist
-Have them cup their hands, like they're holding water in their hands; turn the handplane over and dump the shavings into their hand, saying "Look!  You made these!"
-Next kid

The section inside the red rectangle the cumulative smooth-planing of a classroom of little kids -- plus the vice principal, who had never used a handplane before (by this time, the substitute teacher had arrived).  I also showed her the trick of angling the handplane a bit, to get a lower effective cutting angle against the wood.

So!  A blitz of information.  My hope is that at least some of the kids will remember:

-The difference between a hammer and a mallet, and

-That when you use a handplane, you point your finger (most people don't know that).


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